Link from Facebook post to October CMS production site reports an error

Hi,
I have created new Facebook post with a link to October CMS production site: sperlingdxp.com
Facebook reports an error in preview:

SPERLINGDXP.COM
Page error

However, the site itself runs fine. Also the link from the post published wirks fine.
Any idea what could this behaviour cause?
Thanks.
Milan

Hi

Make sure that your shared url and canonical url are using the same protocol (https:// or http:). If you are sharing http:// and the canonical url is set to https://, you will probably receive a 500 response code. You can use this tool to troubleshoot posts: Sharing Debugger - Facebook for Developers.

Hope this helps.

Thanks a lot, it works fine now.
Rgds,
Milan